Method for reprocessing a device having a plurality of internal passageways

ABSTRACT

A method for the reprocessing of a device having internal passageways by applying a fluid at a plurality of pressures to the internal passageways of the device to permit reuse of the device in a clean environment includes applying a fluid having a single input pressure to a pressure differentiation device having first and second pressure control fittings for providing first and second differing pressure outputs in accordance with the single input pressure and transmitting the fluid at the first and second differing pressures from the pressure differentiation device to the internal passageways. The internal passageways are reprocessed with the transmitted fluid at the first and second differing pressures, whereby the internal passageways are reprocessed at differing pressures in accordance with the single input pressure.

BACKGROUND OF THE INVENTION

[0001] Field of Invention

[0002] This invention relates generally to a method for the reprocessingof a contaminated device having internal passageways before such adevice is reused in a clean environment. The term “reprocessing,” asused herein constitutes the washing, disinfecting, sterilizing and/orpasteurizing of such a device. The term “device” as used hereinconstitutes any devices having internal passageways that require suchreprocessing, including, but not limited to, medical instruments andmedical devices. The terms “medical instrument” and “medical device” areunderstood to constitute devices having one passageway or a plurality ofpassageways, including, but not limited to endoscopes, colonoscopes, andother flexible and rigid medical instruments.

[0003] Some automated systems for reprocessing devices having internalpassageways for reuse are generally available and are commonly reliedupon. For example, systems for reprocessing medical instruments havingpassageways are used by hospitals to safeguard patients and hospitalsemployees from exposure to infection and cross-contamination. Such priorart reprocessing units are manufactured by several different companiesincluding, Custom Ultrasonics, Inc., of Ivyland, Pa., the assignee ofthe present invention and application. For example there arereprocessing units in the prior art adapted for cleaning, disinfectingand sterilizing flexible scopes, e.g., upper and lower gastrointestinalscopes, colonoscopes and duodescopes.

[0004] Prior art reprocessing systems, suitable in particular forreprocessing medical instruments, operate in accordance with apredetermined protocol of reprocessing steps. The protocol is based uponthe specific cleaning requirements of the particular instruments beingcleaned. The reprocessing steps are precisely timed and sequenced inorder to assure optimal results, based upon the correct combination ofwater temperature, detergent and chemical agents. Thus, parameters suchas wash and rinse cycle time, chemical immersion cycle time and watertemperature and pressure were preset by the reprocessing unitmanufacturer and could not be altered by an end user of the system. U.S.Pat. No. 5,761,069, issued to Weber, et. al. teaches a system forcleaning medical instruments having a database of protocolscorresponding to differing medical instruments for permitting a user toload and execute the protocol corresponding to the instrument beingreprocessed.

[0005] An exemplary protocol for cleaning a medical instrument couldinclude the following reprocessing steps, after the instrument has beenplaced in the cleaning basin of the reprocessing unit: (1) wash theinternal and external surfaces of the instrument with a measureddetergent-water mixture for a preset period of time; (2) activateultrasonic crystals while washing; (3) drain the detergent-water mixtureafter the wash cycle is completed; (4) after draining, rinse theinternal and external surfaces of the instrument with water at a presettemperature for a preset period of time; (5) introduce and circulatedisinfectant over and through the instrument for a preset period oftime; (6) drain the disinfectant from the wash basin; and (7) afterdraining of the disinfectant is complete, rinse the instrument withwater; and (8) re-rinse the instrument with water.

[0006] Prior art reprocessing units adapted, in particular, forreprocessing medical equipment, typically comprise a variety ofmechanical components, e.g., pumps, tubes, solenoid valves, ultrasonictransducers, heaters and probes that perform the various reprocessingsteps. The pumps used in these units must be very precise and reliableover extended periods of time. Thus, pumps that are suitable for theseunits can be quite expensive.

[0007] In many cases it is necessary to reprocess devices havingpassageways of differing diameters. The differing diameters can occur ina single device having passageways of differing diameters, or inmultiple devices, each having a single differing diameter. The presenceof differing diameter passageways creates a need for fluid flows ofcorresponding differing pressures, because more narrow passagewaysrequire a higher pressure to force fluid therethrough. Prior artreprocessing units suitable for reprocessing devices having passagewaysof differing diameters included a plurality of pumps and associatedtubing systems, wherein each pump provided one of the differingpressures required to reprocess the differing passageways of thedevices.

[0008] Furthermore, some devices can have extremely narrow passageways,requiring dedicated high-pressure pumps that are capable of providingextremely high pressures. Pumps for such extremely narrow, high-pressurepassageways have very low flow rates. Flow rates that are this low aredifficult to monitor. For example, the flow rates of fluids through thepassageways of some devices can be on the order of a drop a minute.Passageways this narrow can be found, for example, in flexible medicalinstruments, such as endoscopes.

[0009] Known reprocessing units are typically equipped with a pressuresensor for measuring the overall flow of fluid through the pump for thepurpose of detecting obstructions in the passageways of the devices.However, is possible for an obstruction preventing flow of in one of thepassageways to go undetected by the pressure sensor since the flow cancontinue through the remaining passageways and only the overall pressureof the liquid is determined.

[0010] Several governmental and independent agencies have issuedguidelines for reprocessing particular types of medical instruments. Forexample, such guidelines often require that certain types of medicalinstruments be washed and sterilized using a chemical disinfectant,while other types of instruments need only be washed. The design ofreprocessing units and the reprocessing steps they perform must conformto such guidelines. Additionally, guidelines have been created toreliably prevent instruments from being reused if an obstruction occursin a single passageway of a plurality of passageways duringreprocessing. Prior art reprocessing units are not reliably able to meetthese guidelines.

SUMMARY OF THE INVENTION

[0011] A method for the reprocessing of a device having internalpassageways by applying a fluid at a plurality of pressures to theinternal passageways of the device to permit reuse of the device in aclean environment or patient safe environment includes applying a fluidhaving a single input pressure to a pressure differentiation devicehaving first and second pressure control fittings for providing firstand second differing pressure outputs in accordance with the singleinput pressure and transmitting the fluid at the first and seconddiffering pressures from the pressure differentiation device to theinternal passageways. The internal passageways are reprocessed with thetransmitted fluid at the first and second differing pressures, wherebythe internal passageways are reprocessed at differing pressures inaccordance with the single input pressure. The first and second controlfittings can be pressure fittings having respective first and secondopenings. The first and second control openings can have differingdiameters. The pressure differentiation device can be a T-manifold.

[0012] A method for the reprocessing of a device having a plurality ofinternal passageways by applying a plurality of fluid channel flows tothe internal passageways of the device to permit reuse of the device ina clean environment includes applying a pressurized fluid flow to theinput of a manifold having a plurality of manifold outputs for forming aplurality of manifold output channel flows and transmitting the outputchannel flows of the plurality of output channel flows throughrespective flowmeters for measuring an individual flow rate for each ofthe output channel flows. Transmitting the measured output channel flowsto the plurality of internal passageways and reprocessing the internalpassageways using the output channel flows are also included. Anobstruction in an internal passageway of the plurality of internalpassageways is determined in accordance with a measured individual flowrate. The reprocessing of the device is aborted in accordance with thedetermining of the obstruction. An indication of which internalpassageway of the plurality of internal passageways is obstructed isprovided in accordance with a measured individual flow rate.

DESCRIPTION OF THE DRAWINGS

[0013] The features of this invention will become readily appreciated asthe same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

[0014]FIG. 1 is a top plan view of a prior art reprocessing unit whereinthe cover of the reprocessing unit is disposed in an opened position topermit a view of a reprocessing basin containing devices to bereprocessed.

[0015]FIG. 2 is an elevational view of a reprocessing unit suitable foruse with the system and method of the present invention.

[0016]FIG. 3 shows a top view of the reprocessing basin of thereprocessing unit of FIG. 2 including a device to be reprocessed.

[0017] FIGS. 4A-C show top, front and plan views of the pressuredifferentiation device of the reprocessing unit of FIG. 2.

[0018] FIGS. 5A-D are front and side views of the pressure controldevices of the pressure differentiation manifold of FIGS. 4A-C.

[0019] FIGS. 6A-C show top, front and plan views of the pressuredistribution manifold of the present invention.

[0020]FIG. 7 shows a schematic block diagram illustrating the processflow of the operations performed by the reprocessing unit of FIG. 2.

[0021] FIGS. 8A-B show top and front views of a flowmeter of the presentinvention.

[0022] FIGS. 9A-C show top, front and plan views of a pressure sensor ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Referring now to the drawings, wherein like reference numeralsrefer to like parts, there are shown representations of reprocessingsystems and methods suitable for using conventional reprocessingprotocols to reprocess devices having internal passageways, such asmedical instruments. An example of such a reprocessing protocol isdisclosed in U.S. Pat. No. 5,761,069, issued to Weber, et. al., which isincorporated by reference herein.

[0024]FIG. 1 shows a top view of a prior art reprocessing unit 10,wherein a cover (not shown) is disposed in an open position. Thereprocessing unit 10 includes a reprocessing basin 12, the instrumentcarrier 14, and a chemical disinfectant reservoir 16. The instrumentcarrier 14 is shown seated within the reprocessing basin 12. Theinstrument carrier 14 can be generally rectangular in shape andcomprises a mesh-like bottom 18 which is arranged to hold the surgicalinstruments 15 during reprocessing, wherein the surgical instruments 15each include a single passageway therethrough requiring reprocessing.The reprocessing basin 12 is also provided with a plurality of spraynozzles 26 for use during the rinse cycle.

[0025] The instrument carrier 14 includes a manifold assembly 20 havinga plurality of ports 20 a-f, each of which is shown applied to aninternal passageway of a respective surgical instrument 15. In order toreprocess the surgical instruments 15 having a single passageway withinthe reprocessing unit 10, the surgical instruments 15 are disposed onthe instrument carrier 14 for coupling to the ports 20 a-f. Since thesurgical instruments 15 have a single passageway, only a single one ofthe ports 20 a-f is required for each surgical instrument 15. Themanifold assembly 20 is connected to a port 22 by means of a tubingsegment 24, which conducts fluid flow from the port 22 to the manifoldassembly 20 for distribution by way of the ports 20 a-f.

[0026] The fluid flow of the port 22 is driven by an oscillating pump(not shown). The oscillating pump operates to draw fluid, e.g., washwater, rinse water or chemical disinfectant, from the reprocessing basin12, circulate that fluid through the ports 20 a-f and the manifoldassembly 20, and through the respective passageways of the surgicalinstruments 15 disposed on the instrument carrier 14, to effect thedecontamination process during the wash, rinse and chemical immersionphases of the reprocessing protocol.

[0027] In this manner, the pressure delivered to each of the passagewaysof the surgical instruments 15 can be substantially equal in thereprocessing unit 10. Reprocessing unit 10 is thus suitable forreprocessing a plurality of surgical instruments 15 requiring such asingle pressure to be applied to all of the passageways of the surgicalinstruments 15. However, many surgical instruments are provided withpassageways of differing diameters. Such surgical instruments requirediffering pressures, corresponding to the differing diameters, forproviding the required circulation of wash water, rinse water andchemical disinfectants through the passageways.

[0028] Referring now to FIGS. 2, 3, there is shown a reprocessing unit80 suitable for use with the system and method of the present invention,and a view of a reprocessing basin 12 within the reprocessing unit 80.The reprocessing basin 12 holds a device 96 having internal passageways98 a-e for reprocessing of the device 96 by the reprocessing unit 80. Ina preferred embodiment of the invention, the device 96 being reprocessedby the reprocessing unit 80 can be a medical instrument 96. Inparticular, the system and method of the invention are well suited forapplication to medical instruments including flexible scopes such asendoscopes that are used for upper and lower gastrointestinal studies.

[0029] The reprocessing unit 80 includes a keyboard 40, a monitor 28, aprinter 32, and an associated personal computer (not shown) forpermitting a user of the reprocessing unit 80 to communicate with andcontrol the reprocessing unit 80. The reservoir 16 of the reprocessingunit 80 includes the sensors 34, 36, 38 for controlling devices such asa heater, a pump and a vacuum device (not shown) in order to protectagainst failure conditions such as overflow conditions in the reservoir16. A removable door 42 within the reprocessing basin 12 coversadditional sensors (not shown) for providing further operationalcapability and safety protection during the operation of thereprocessing unit 80. The door stops 30 are provided to stop the motionof the rotatable doors 31 covering the reservoir 16 and the reprocessingbasin 12 when they are opened.

[0030] In the preferred embodiment, the reprocessing basin 12 can holdmore than one device 96 upon a mesh for reprocessing of the internalpassageways 98 a-e thereof according to conventional reprocessingprotocols. The reprocessing unit 80 is adapted to provide fluid flows ofdiffering pressures to the device 96 or devices 96 being reprocessedwhen the internal passageways 98 a-e have differing diameters. Thereprocessing unit 80 is adapted to perform the multi-pressurereprocessing operations using a single pump (not shown), and to providean indication of an obstruction in any of the internal passageways 98a-e of the device or devices 96 as described in more detail below. Thesingle pump of the reprocessing unit 80 can be a diaphragm pump, anoscillating pump, or any other type of pump known to those skilled inthe art.

[0031] The reprocessing basin 12 includes the supply ports 123 a-l thatcan be selectively used to apply fluids at different fluid flow rates tothe medical instruments 96 for reprocessing of the medical instruments96. For example, the supply port 123 j can be capped and reserved foruse when needed. The supply port 123 a can be used to blow off a fluidflow which is unusable due to difficulty in regulating and measuringtheir flow rates, as described in more detail below. In this example, atleast the supply ports 123 a-l that are not capped or blown off can bevented into the reprocessing basin 12 or coupled to the internalpassageways 98 a-e of a medical instrument 96 as needed.

[0032] For example, an internal biopsy passageway 98 a of the medicalinstrument 96 can be coupled to the supply port 123 b by way of thetubing segment 132 b, and an internal water channel passageway 98 b ofthe medical instrument 96 can be coupled to the supply port 123 c by wayof the tubing segment 132 c. The internal passageway 98 c can be coupledto the supply port 123 d by way of the tubing segment 132 d, and theinternal suction passageway 98 d can be coupled to the supply port 123 eby way of the tubing segment 132 e. The internal elevator water channelpassageway 98 e can be coupled to the supply port 123 l by way of thetubing segment 132 l.

[0033] The disk filters 94 and their tubing extensions can be disposedin line with the selected passageways 98 a-e for preventing debris fromreaching the medical instrument 96. For example, the disk filters 94 canbe provided in the tubing segments 132 c,d,e. The device for couplingthe selected tubing segments 132 a-l to the tubing extensions of thedisc filters as shown can be the well known lure lock type of coupling.Typical diameters for some of the passageways 98 a-e can be 0.508millimeters to 4.8 millimeters.

[0034] Referring now to FIGS. 4A-C, there is shown a pressuredifferentiation device 252 for providing fluid flows of differingpressures from the output of a single conventional pump that provides asingle pump output pressure. It is the different output pressures at theoutput of the pressure differentiation device 252 that are applied byway of the selected supply ports 123 a-l to the internal passageways 98a-e of the medical instrument 96 for reprocessing the medical instrument96 or any other device 96 having such passageways 98 a-e. The singlepump applied to the pressure differentiation device 252 can be aconventional diaphragm type pump, an oscillating pump, or any other typeof pump known to those skilled in the art. The pressure differentiationdevice 252 can be a conventional T-manifold that is known to thoseskilled in the art.

[0035] The single pump output pressure is applied to the pressuredifferentiation device 252 at an input port 251 a for application to thetwo output ports 251 b,c of the pressure differentiation device 252. Theoutput ports 251 b,c threadably receive and secure different pressurecontrol devices which can have openings of different diameters, asdescribed in more detail below. The pressure control devices secured inthe output ports 251 b,c permit the pressure differentiation device 252to provide two different pressures for the internal passageways 98 a-eof the medical instruments 96. In the preferred embodiment the outportport 251 b can be a high pressure output port and the output port 251 ccan be a low pressure output port.

[0036] In a typical embodiment of the invention, the higher pressure ofthe high pressure output port 251 b of the pressure differentiationdevice 252 can be approximately 25 to 50 pounds per square inch. Thelower pressure of the low pressure output port 251 c can beapproximately 2 to 20 pounds per square inch. The pressures at theoutput ports 251 b,c can fluctuate within these ranges depending onfactors such as the number of medical instruments 96 coupled to thereprocessing unit 80. It will be understood by those skilled in the artthat a pressure differentiation device 252 having additional outputports with different pressure control devices can be used forreprocessing systems 80 requiring more than two differing pressures.

[0037] Referring now to FIGS. 5A-D, there are shown the pressure controldevices 257, 259 of the pressure differentiation device 252 forproviding the two different pressures to the internal passageways 98 a-eof the medical instrument 96. The pressure control devices 257, 259 canbe conventional pressure control orifice fittings 257, 259 that arethreadably received and secured in the output ports 251 b,c of thepressure differentiation device 252. The two different pressures areprovided at the output ports 251 b,c when a single pressure is appliedto the input port 251 a of the pressure differentiation device 252because of the different diameters of the openings within the pressurecontrol orifice fittings 257, 259. The pressure control orifice fitting257 is a high pressure orifice fitting and the pressure control orificefitting 259 is a low pressure orifice fitting.

[0038] In the preferred embodiment of the invention, the pressuredifferentiation device 252 can be formed with an entrance 260 forpermitting an FDA approved liquid chemical sterilant as well as alcoholto be injected into the fluid stream passing through the device 252 fortransmission through the selected supply ports 123 a-l of thereprocessing basin 12 to the medical instruments 96. A disinfectantinjection bulkhead communicating with the entrance 260 can be located onthe exterior of the reprocessing unit 80 for convenience. Additionally,a filter (not shown) can be disposed in a conduit from the pump to theinput port 251 a of the device 252 for filtering fluid in transit to theinternal passageways 98 a-e. The filter can be, for example, aone-hundredth micron filter.

[0039] Referring now to FIGS. 6A-C, there are shown representations ofthe pressure distribution manifold 250 of the reprocessing unit 80,including the manifold input ports 253, 255, and the manifold outputports 121 a-l. The pressure distribution manifold 250 can be aconventional air manifold understood by those skilled in the art. It isadapted to receive the fluid flows of the two different pressures fromthe output ports 251 b,c of the pressure differentiation device 252 byway of the manifold input ports 253, 255. The fluid flows from thepressure distribution manifold 250 are applied by way of the manifoldoutput ports 121 a-l directly to the corresponding supply ports 123 a-lof the reprocessing unit basin 12. Therefrom, they are selectivelyapplied to the devices 96 such as the medical instruments 96. In thepreferred embodiment, the manifold output ports 121 a-j are low pressureports and the manifold output ports 121 k,l are high pressure ports.

[0040] A high pressure fluid flow is received at the high pressuremanifold input port 253 of the pressure distribution manifold 250 fromthe orifice port 251 b of the pressure differentiation device 252. Ashort longitudinal bore hole 140, opening at the high pressure manifoldinput port 253, is provided at one end of the pressure distributionmanifold 250. The pressure distribution manifold 250 is boredtransversely from each of the high pressure manifold output ports 121k,l to the longitudinal high pressure bore hole 140 in order to permitthe high pressure output ports 121 k,l to communicate with the highpressure bore hole 140. Thus, a high pressure fluid flow applied to theinput port 253 of the pressure distribution manifold 250 is distributedto the high pressure, or narrower inner diameter, passageways of themedical instruments 96 by way of the high pressure bore hole 140 and themanifold output ports 121 k,l.

[0041] A low pressure fluid flow is received at the low pressure inputport 255 of the pressure distribution manifold 250 from the output port251 c of the pressure differentiation device 252. A long longitudinalbore hole 142, opening at the low pressure manifold input port 255, isprovided within the pressure distribution manifold 250. Substantially asdescribed with respect to the high pressure output ports 121 k,l,transverse bore holes extending from the low pressure output ports 121a-j to the longitudinal low pressure bore hole 142 are provided. Thus,the low pressure manifold output ports 121 a-j communicate with the lowpressure bore hole 142. In this manner, a low pressure fluid flowapplied to the low pressure input port 255 of the pressure distributionmanifold 250 is distributed to the low pressure passageways of themedical instruments 96 by way of the low pressure bore hole 142 and themanifold output ports 121 a-j.

[0042] Those skilled in the art will understand that possible turbulenceat the distal end of the pressure distribution manifold 250, in theregion of the manifold output port 121 a can make the flow ratesdifficult to measure and/or difficult to control. Therefore, in thepreferred embodiment of the invention, the fluid flows provided by wayof the supply port 123 a can be blown off into the reprocessing basin12, rather than applied to a medical instrument 96.

[0043] The pressure measurement openings 144 on the side of the pressuredistribution manifold 250 individually communicate with the longitudinalbore holes 140, 142. The presence of the pressure measurement openings144 on the pressure distribution manifold 250 permits measurement of thepressures within the bore holes 140, 142, as described in more detailbelow.

[0044] Referring now to FIG. 7, there is shown a block diagramrepresentation of a process flow 95 for performing a reprocessingprotocol within the reprocessing unit 80 suitable for reprocessingdevices such as the medical instruments 96. During a fill step of theprocess flow 95, a solenoid-type water valve 230 is placed in an openposition to enable water to flow from an outside hot/cold water source232 through a water line 234, into the reprocessing basin 12 to immersethe medical instrument 96. The reprocessing basin 12 is provided with adrain 44 (shown in FIG. 2) located in the bottom of the reprocessingbasin 12. The drain 44 is connected to a drain line 212. During the fillstep, as wash water flows into the reprocessing basin 12 it begins todrain through the drain line 212. A drain valve 164, provided below thedrain line 212 is normally in a closed state to prevent the draining ofthe water out of the system. This action enables the filling of thereprocessing basin 12.

[0045] A flow probe 220 is located adjacent the drain line 212 and isoperative to detect the presence of liquid as wash water begins to fillthe drain line 212 during filling of the reprocessing basin 12. Once theprobe 220 detects the presence of moisture, the probe 220 sends a signalindicative thereof to a system controller which provides an indicationto the user that the reprocessing basin 12 is filling with water.Additionally, an operational float (not shown) is located within thereprocessing basin 12. During filling, the operational float is buoyedupwardly and eventually reaches a predetermined height corresponding toa particular volume of wash water being present in the reprocessingbasin 12. When the operational float reaches this predetermined level,the reprocessing unit 80 indicates to the user that the reprocessingbasin 12 has been filled and that the washing step can begin.Thereafter, the water valve 230 is closed so that no additional washwater enters the reprocessing basin 12.

[0046] As wash water fills into the reprocessing basin 12 over theimmersed medical instruments 96, a solenoid-type detergent valve 262 anda detergent pump 266 operate to withdraw a predetermined amount, e.g.,three ounces, of detergent 254 from a detergent container 258 locatedadjacent the reprocessing unit 80 and inject the predetermined amount ofdetergent into the reprocessing basin 12 through a detergent line 264.The detergent 254 may be of any suitable composition. One particularlyeffective type of detergent is sold under the trademark TERGAL 800 byCustom Ultrasonics, Inc.

[0047] During the wash step, a pump 246, such as a diaphragm pump, isactivated to draw the water/detergent mixture contained in thereprocessing basin 12 through an intake valve 240 and to circulate themixture through the circular reprocessing basin 12, the output ports 121a-l of the pressure distribution manifold 250, the tubing segments 132a-l, and through the internal passageways 98 a-e of the immersed medicalinstrument 96. Any unused output ports 121 a-l can be blown off into thebasin 12. The pump 246 is a single output pressure pump. In this mannerfluid is recirculated through the immersed medical instrument 96 for apredetermined period of time in order to reprocess the internalpassageways of the internal medical instrument 96 in accordance with apredetermined reprocessing protocol.

[0048] Referring now to FIGS. 8A-B, there is shown a flowmeter 256 forselectively coupling to the manifold output ports 121 a-l andindividually measuring the flow rates of the fluids within the manifoldoutput ports 121 a-l of the reprocessing unit 80 coupled thereto. Theflowmeter 256 can be any conventional flow sensor suitable for measuringthe flow rate through the ports 121 a-l, and thereby through the tubingsegments 132 a-l. For example, the flowmeter 256 can be an in linestraight-through flow tube sensor that uses ultrasonic sensingtechnology to measure the rate of flow of a fluid passing therethrough,such as the M-1500 Series provided by Malema Flow Sensors. The flowmeter256 can be omitted from any unselected output ports 121 a-l notsupplying fluid to any internal passageways, for example the outputports 121 a which is blown off into the reprocessing basin 12.

[0049] An ultrasonic sensing flowmeter 256 is preferred because it isnon intrusive, thereby permitting the fluid flow to the internalpassageways 98 a-e of the medical instruments 96 to be measured withoutinterference by the flowmeter 256. Ultrasonic sensing flowmeters 256 ofthis type are believed to be accurate from one-half cubic centimeter perminute to infinity for a multiple number of outputs.

[0050] The flowmeter 256 provides a flow rate signal according to themeasured flow rate, for example by tripping a switch within theflowmeter 256 when the flow rate falls below a predetermined value.

[0051] In another embodiment of the invention, the flowmeters 256 can beof the well know piston type, wherein the force of the fluid flowthrough the flowmeter 256 raises and suspends a piston therein, untilthe flow rate falls below a predetermined value. When the flow ratefalls below the predetermined value, the piston falls and a switchwithin the flowmeter 256 is tripped. The tripping of the switch withinthe flowmeter 256 indicates that the predetermined flow rate through theflowmeter 256 has not been maintained. It is believed that a flowmeter256 of this type is not as accurate the ultrasonic type since it caninterfere with the fluid flow being measured.

[0052] In one preferred embodiment of the invention, the minimum flowrate through the high pressure ports 121 k,l can be approximately onecubic centimeter per minute. The minimum flow rate through the two lowerpressure ports 121 a,b at the distal end of the pressure distributionmanifold 250 can be approximately fifty cubic centimeters per minute.The minimum flow rate through the remaining low pressure ports 121 c-jcan be 0.05 gallons per minute.

[0053] Thus, the flowmeters 256 disposed in line with the internalpassageways 98 a-e provide an indication to the user of the reprocessingsystem 80 when the flow through any of the passageways 98 a-e of thesurgical instruments 96 coupled to the reprocessing unit 80 isobstructed. When any of the internal passageways 98 a-e is determined tobe obstructed in this manner, the reprocessing operation set forth inthe process flow 95 is aborted, and the abort condition is communicatedto the user of the reprocessing unit 80. This feature prevents theinadvertent reuse of any device 96 that has not been completelyreprocessed due to an obstruction in any of the internal passageways 98a-e being reprocessed. Without such a feature the operator can be leftwith a false sense of security regarding the success of the reprocessingoperation.

[0054] In the preferred embodiment of the invention, individualindicator lights (not shown) corresponding to each flowmeter 256 coupledto the pressure distribution manifold 250 are mounted on the exterior ofthe reprocessing unit 80. The indicator lights permit an easy visualdetermination of which internal passageway 98 a-e is obstructed when thereprocessing operation is aborted. Additionally, in one preferredembodiment of the invention, a lag time of approximately ten seconds canbe provided between the detection of an obstruction by a flowmeter 256and the abort of the reprocessing operation to allow for the breaking upof an obstruction due to back pressure provided by the pump.

[0055] Referring now to FIGS. 9A-C, there are shown representations ofthe pressure sensing switch 320 of the reprocessing unit 80. Thepressure sensing switch 320 is adapted to measure the pressure of thelongitudinal bore holes 140, 142 within the pressure distributionmanifold 250, and to provide an electrical pressure signal according tothe measured pressure of the bore holes 140, 142.

[0056] In an alternate embodiment of the invention (not shown) aflowmeter 256 coupled to a manifold output port 121 a-l of the pressuredistribution manifold 250 can be omitted. In such an embodiment, thepressure sensing switch 230 is mounted in a pressure measurement opening144 communicating with a longitudinal bore 140, 142 of the pressuredistribution manifold 250. For example, the flowmeters 256 can beremoved from the manifold output ports 121 k,l, and the high pressureflow rate can be measured by a pressure sensing switch 320 mounted inthe pressure measurement opening 144 disposed in communication with thelongitudinal bore hole 140.

[0057] Thus, the pressure of the manifold output ports 121 k,l ismonitored using the pressure sensing switch 320 rather than measuringthe fluid flow rate using a flowmeter 256. In this alternate embodiment,an obstruction within a high pressure passageway of the medicalinstrument 96 is detected by sensing a change in pressure rather than achange in flow rate. Thus, the reprocessing of the instrument 96 isaborted according to the pressure measured by the pressure sensingswitch 320 rather than a direct measurement of flow rate. In oneembodiment of the invention the pressure sensing switch 320 can beadapted to provide an electrical pressure signal when the measuredpressure is at a level in the range of 1.5 to 15 psi.

[0058] In another alternate embodiment (not shown) of the reprocessingunit 80 an ultrasonic flow sensor such as the flowmeter 256 can bemounted on the pressure distribution manifold 250, for example, at theinput end of the pressure distribution manifold 250. This type ofultrasonic measurement of flow rate is extremely sensitive, allowing thedetection of changes in flow rate as small as a few drops per second.The reprocessing operations of the process flow 95 are aborted when theflow detected by such an ultrasonic measurement device mounted on thepressure distribution manifold 250 in this manner is below thepredetermined level.

[0059] Once the water/detergent mixture has passed through the internalpassageways 98 a-e of the immersed medical instrument 96, it flows backinto the reprocessing basin 12 where it is again recirculated by thepump 246 for a predetermined minimum period of time based uponguidelines provided by the detergent manufacturer, e.g., one-hundredeighty seconds. During the wash step, the ultrasonic crystals 282located below the reprocessing basin are activated. When activated, theultrasonic crystals 282 generate ultrasonic vibrations that act incombination with the detergent-water mixture to cause a cleansing actionthat breaks down, loosens and removes contaminants from the exterior andinterior surfaces of the flexible medical instrument 96 to provideenhanced cleaning.

[0060] Once the predetermined time period for the wash step has elapsed,the drain step begins. During the drain step, the drain valve 164 isopened and the drain pump 216 is activated. While the pump 246 continuesto pump the water/detergent mixture through the medical instrument 96,the mixture begins to drain out of the reprocessing basin 12 by means ofthe drain pump 216 which pumps the water/detergent mixture down thedrain line 212 and into a T-assembly 217. The mixture travels throughdrain valve 164, through a standpipe 165 and into a sewer drain 167.Once the flow probe 220 detects the absence of moisture in the drainline 212, the drain pump 216 is shut off and the drain valve 164 isreturned to its closed position.

[0061] After the drain pump 216 is shut off, an air pump 224 isactivated and a solenoid-type air valve 226 is opened. By use of the airpump 224 forced air is directed through the pump 246, the manifoldassembly 250, the tubing segments 132 a-e, and through the internalchannels of the medical instrument 96. The forced air acts to purge andclear away any residual water/detergent mixture remaining in theinterior channels of the medical instrument 96. The purged residualwater/detergent mixture flows down the drain line 212 located below thereprocessing basin 12 and collects in the bottom of the T-assembly 217located below the drain line 212. The purged residual water/detergentmixture is removed from the bottom of the T-assembly 217 by means of aresidual drain line 310 and a residual drain pump 314 that is activatedsimultaneously with the air pump 224.

[0062] The first rinse cycle comprises the steps of fill, rinse anddrain steps. During the fill step, water is introduced into thereprocessing basin 12 from the outside source 232 by means of watervalve 230 and water line 234. Since this is a rinse cycle, as opposed toa wash cycle, no detergent 254 is introduced during the fill step.During the rinse step of the process flow 95, the pump 246 draws therinse water contained in the reprocessing basin 12 through the intakevalve 240 and recirculates the rinse water for a predetermined minimumperiod of time in a manner as previously described above in connectionwith the wash step. Also, during the rinse step, the ultrasonic crystals282 are activated.

[0063] Thereafter, the drain step begins. During the drain step, rinsewater is pumped out of the reprocessing basin 12 by the drain pump 216.The water travels down the drain line 212 through the drain pump 216 andinto the T-assembly 217. Because the drain valve 164 is in the openedposition, the water travels through drain valve 164 and throughstandpipe 165 and into a sewer drain 167.

[0064] Once the flow probe 220 detects the absence of moisture in thedrain line 212, the drain pump 216 is shut off. Some residual waterremains in the bottom of the T-assembly 217 that cannot be removed bythe drain pump 216. This residual rinse water is removed from the bottomof the T-assembly 217 by means of the residual drain line 310 and theresidual drain pump 314 in the manner previously described. By removingall residual rinse water from the T-assembly 217, chemical disinfectantintroduced in the next step of the protocol will not become diluted withany residual rinse water.

[0065] Once the drain step 141 is complete and all residual rinse waterhas been removed from the T-assembly 217, the next fill step begins anda chemical disinfectant 288 is introduced into the reprocessing basin12. One particularly effective type of chemical disinfectant is 2% or 3%glutaraldehyde which is marketed by a number of different companiesunder various brand names such as Cidex manufactured by Johnson &Johnson. The introduction of the disinfectant 288 is effected by openinga reservoir feed valve 298 to cause a reservoir pump 294 to pump thechemical disinfectant 288 from a chemical disinfectant reservoir 290through a chemical line 306 into the reprocessing basin 12. The chemicaldisinfectant 288 enters and fills the reprocessing basin 12 to apredetermined height as previously described.

[0066] Once the reprocessing basin 12 has been filled with the chemicaldisinfectant 288 to the predetermined level, the pump 246 is activatedto draw the chemical disinfectant 288 contained in the reprocessingbasin 12 through the intake valve 240. This action circulates thechemical disinfectant 288 through the ports of the manifold 250, thetubing segments 132 a-e and through the internal passageways 98 a-e ofthe immersed medical instrument 96. Once the chemical disinfectant 288has passed through the internal passageways of 98 a-l of the immersedmedical instrument 96, it flows back into the reprocessing basin 12where it is recirculated by the pump 246 for a predetermined minimumperiod of time based upon guidelines provided by the manufacturer of thechemical disinfectant 288. Once the predetermined minimum time periodfor the chemical immersion step has elapsed, the pump 246 is turned off.

[0067] Thereafter, the chemical disinfectant 288 is returned to thechemical disinfectant reservoir 290 for reuse. To enable the return ofthe chemical disinfectant 288 to the reservoir 290, the drain valve 164is closed and the reservoir return valve 302 is opened. The drain pump216 is activated and the chemical disinfectant 288 is pumped through thechemical line 306, through the reservoir return valve 302 and back intothe chemical reservoir 290. Once the flow probe 220 detects the absenceof moisture in the drain line 212, the drain pump 216 is tuned off.Thereafter, two additional rinse cycles are performed. The first rinsecycle comprises a first rinse and a drain phase. The rinse cycle isperformed in a manner similar to the rinse cycle previously described.However, this rinse cycle does not include use of the residual drainline 310 and residual drain pump 314. The ultrasonic crystals 282 areactivated during the rinse step of this rinse cycle.

[0068] The second rinse cycle comprises fill, second rinse and drainphases. This rinse cycle is performed in a manner similar to the rinsecycle previously described, i.e., fill, rinse and drain phases, andincludes use of the residual drain line 310 and residual drain pump 314.The ultrasonic crystals 282 are activated during the rinse step of thisrinse cycle. Once this rinse cycle has been completed, the reprocessingprotocol is complete and the instrument may be removed from thereprocessing chamber for reuse.

[0069] Without further elaboration, the foregoing will so fullyillustrate the invention that others may, by applying current or futureknowledge, readily adapt the same for use under the various conditionsof service.

1. A method for the reprocessing of a device having internal passagewaysby applying a fluid at a plurality of pressures to said internalpassageways of said device to permit reuse of said device in a cleanenvironment, comprising the steps of: (a) applying a fluid having asingle input pressure to a pressure differentiation device having firstand second pressure control fittings for providing first and seconddiffering pressure outputs in accordance with said single inputpressure; (b) transmitting said fluid at said first and second differingpressures from said pressure differentiation device to said internalpassageways; and (c) reprocessing said internal passageways with saidtransmitted fluid at said first and second differing pressures, wherebysaid internal passageways are reprocessed at differing pressures inaccordance with said single input pressure.
 2. The method for thereprocessing of a device of claim 1, wherein said first and secondpressure control fittings comprise pressure controls fittings havingrespective first and second control openings.
 3. The method for thereprocessing of a device of claim 2, wherein said first and secondcontrol openings have differing diameters.
 4. The method for thereprocessing of a device of claim 3, wherein said pressuredifferentiation device comprises a T-manifold.
 5. The method for thereprocessing of a device of claim 1, comprising the further steps ofproviding a pressure distribution manifold and applying said first andsecond pressures from said pressure differentiation device to saidpressure distribution manifold.
 6. The method for the reprocessing of adevice of claim 5, comprising the further steps of: (a) applying saidfluid at said first and second pressures from said pressure distributionmanifold to respective first and second pluralities of tubing segments;(b) transmitting said fluid at said first pressure by way of a tubingsegment of said first plurality of tubing segments to a first internalpassageway of said plurality of internal passageways, said firstinternal passageway having a first diameter; and (c) transmitting saidfluid at said second pressure by way of a tubing segment of said secondplurality of tubing segments to a second internal passageway of saidplurality of internal passageways, said second internal passagewayhaving a second diameter differing from said first diameter.
 7. Themethod for the reprocessing of a device of claim 6, wherein said devicecomprises a medical instrument.
 8. The method for the reprocessing of adevice of claim 7, wherein said medical instrument comprises a flexiblescope.
 9. The method for the reprocessing of a device of claim 7,wherein said medical instrument comprises at least one internalpassageway of each of said first and second diameters coupled to tubingsegments of each of said first and second pluralities of tubingsegments.
 10. The method for the reprocessing of a device of claim 7,comprising a first medical instrument having an internal passageway ofsaid first diameter and coupled to a tubing segment of said firstplurality of tubing segments and a second internal passageway of saidsecond diameter and coupled to a tubing segment of said second pluralityof tubing segments.
 11. The method for the reprocessing of a device ofclaim 6, further comprising a flowmeter disposed in line with a tubingsegment of said first and second sets of tubing segments.
 12. The methodfor the reprocessing of a device of claim 11, further comprising aplurality of flowmeters, each flowmeter being disposed in line with atubing segment of said first and second pluralities of tubing segments.13.-37. (Canceled)